This invention relates to the operation of a touch screen. A touch screen is an electronic touch-sensitive display capable of detecting the presence and location of one or multiple touches within the graphical display area and actuating programmed commands accordingly. Being flexible, simple, and intuitive, user interfaces based on touch screen technology have become essential to a large variety of electronic devices such as personal digital assistants, mobile phones, electronic book readers, computers, navigation devices, and point-of-use terminals.
A typical touch screen features a uniformly constructed planar surface having a plurality of touch activation areas correlative with predetermined functional commands. Although these touch activation areas often display graphics that visually emulate conventional buttons or keys, a user's experience of touching these buttons or keys is fundamentally different due to the lack of tactile cues and feedback that conventional buttons and keys would provide. As a result, a user will have to rely on visual sense to identify a touch target on the touch screen and align a touch instrument with the target to actuate an intended command. Additionally, a user frequently uses a finger as the touch instrument to interact with a touch screen, which can further elevate the difficulty of operation because a touch screen is typically less responsive to a human finger than to a more rigid and pointed apparatus such as a stylus or a shaped button. These factors contribute to touch screen devices being inefficient, error-prone, and frustrating or even unsafe to operate in many situations especially where the circumstances of operation do not permit extended visual involvement.
One of such situations is the use of a portable navigation device, commonly known as a Global Positioning System (GPS) device, while operating a mobile vehicle. Most drivers find it necessary or very beneficial to view additional information or adjust map scale on the device screen while driving. This is usually done by touching one or more emulated buttons on the touch screen. However, the amount of visual attention paid to identifying and locating correct touch controls can be excessive, consequently leading to unsafe driving. Other scenarios of conventional touch screen interfaces being undesirable or less-efficient include playing video games on a handheld touch screen device such as a mobile phone, entering information using emulated keys on a touch screen, controlling a production line with a touch screen terminal, and so on.
Prior to this invention, there were practices offering alternative interfaces to touch screens. For example, a voice command system can be incorporated into touch screen devices, such as a GPS unit, to replace certain touch screen functions. However, it is an expensive feature and is not nearly as reliable as touch controls due to current state of the technology and its inherent shortcomings such as sensitivity to noise in the operating environment. Another alternative is to add physical buttons somewhere on the housing of a touch screen device, but similarly their benefits appear to be outweighed by their added complexity, increased device size, and less intuitive user-interfaces.
There were also approaches intended to alleviate this problem with simulated touch sensation. One method is to include electric motors with vibration-generating mechanisms inside touch screen devices so that a user's touch actuation of a touch command can also trigger some vibrating effects for tactile feedback. Although it may be desirable to have at least this kind of simulated tactile confirmation upon actuating a touch command, it leaves the needs for better identification and location of touch targets unaddressed.
Others attempts have also been brought forward around the idea of adding tactile feels base on certain hardware structures. One example was seen in the mobile phone industry where a touch screen phone was equipped with a flip cover having physical keys corresponding to touch activation commands on the touch screen. When the cover is closed relative to the touch screen, it allows a user to experience a traditional push-key type keypad by transmitting user's touch pressure to touch activation areas beneath the cover. If the user wants to view and use other functions on the same touch screen area without inference, the cover must be flipped open and typically disposed at a fixed angle to the touch screen, occupying a large space. This type of devices has not gained much popularity, however, possibly due to the drawbacks including much increased device form factor especially when the cover is in the open position as well as blocked or diminished views of the touch screen when the cover is closed.
For another example, some have conceived the use of a flexible membrane, such as a screen-protector type overlay, with some tactile surface shapes covering at least a portion of a touch screen where emulated keyboard is present. The apparent problem with this method is the difficulty in removing and re-applying the overlay as needed, and there has not been evidence of systemic considerations and designs to actually support permanent presence of such overlays on touch screens without noticeably affecting the views and/or controls of the touch screens. Some have suggested incorporating complex and expensive mechanisms such as a motorized system to dispose and retract such overlay membrane, but that seems to have significant economic disadvantages and yet to be tested for operability and reliability.
For yet another example, some have suggested placing a rigid keyboard structure over a touch screen and using it to press the touch screen for data entry instead of directly dealing with an emulated on-screen keyboard that can be very small on a hand-held device such as a mobile phone. However, there are issues limiting the benefits and drawbacks hindering actual applications. For instance, a physical keyboard structure may often comprise very small keys as limited by the compact form factor of the device, and such keys are still difficult, unforgiving to touch. Artificially making the keys larger and adding additional supporting structure will likely result in unacceptable bulkiness from a user's perspective. Another unaddressed or under-addressed issue, similar to that in the flexible membrane example, is how to integrate the apparatus with existing touch screen devices in a convenient, user-friendly fashion and without unwanted problems such as noticeably increased form factor and lack of storage solutions. For instance, a user trying a clip-on keyboard structure will likely struggle to find a proper place to store it for reuse. Additionally, emulated keyboard layouts often shift locations or even change orientations on touch screens, making this type of keyboard overlay useless in such situations.
In summary, a user trying to apply these ideas may well encounter new major problems while addressing the original issue. It is also hardly seen any cost-effective, convenient, and universal apparatus that can be adopted by various devices. In addition, it appears that existing touch screen systems are not programmably optimized or streamlined in light of control placement, sequencing, etc. to support better operation of touch screen devices.
Because of such drawbacks and deficiencies associated with current practices and improvement attempts, the mainstream method of operating touch screens today still entails the use of a conventional touch instrument such as a stylus or a human finger to interact with touch commands, resulting in compromised user experiences. Thus, there remain broad needs for practical and optimal solutions that are simple and versatile to adopt, convenient to use, and truly user-friendly from a systemic perspective so that touch screen devices can be easier, more productive, and safer to use.